Log aligning device



Filed Sept. 28, 1960 m m 5 P\ m 2 Inventor Attorney "we I United States Patent 3,009,559 LOG ALIGNING DEVICE Peter Suttie, Baie Comeau, Quebec, Canada, assignor to The Ontario Paper Company Limited, Thorold, 0ntario, Canada Filed Sept 28, 1960, Ser. No. 58,970 9 Claims. (Cl. 198-29) This invention relates to a device for aligning logs. More particularly this invention relates to a log aligning device for aligning logs endwise so as to facilitate the selection and separation of logs for future operations.

A log aligning device constructed in accordance with my invention is particularly useful in the pulp and paper industry, but it will be appreciated that it may have numerous other uses as well.

In the pulp and paper industry it may be necessary to align the logs coming from the barking drum or other apparatus so that the logs can be readily viewed and selectively separated for use in future operations, e.g., it may be necessary to separate those logs destined for mechanical pulping operations from those that should be treated by a chemical pulping process.

Accordingly it is a primary object of my invention to provide a log aligning device which operates to align logs endwise in such a manner that the logs may be readily separated or graded.

Another object of my invention is to provide such a device as may be readily manufactured.

A further object of my invention is to provide an automatic log aligning device.

Other objects and advantages of my invention will become apparent from the following description taken in conjunction with the attached figure which shows, partly in section, a preferred embodiment of my log aligning device.

In brief, a log aligning device constructed in accordance with my invention comprises conveying means for conveying a plurality of logs lying one beside another in substantially parallel relationship, a backstop positioned on one side of the conveying means and a log aligning apparatus positioned opposite the backstop on the other side of the conveying means. The log aligning apparatus includes a cylinder having an open end, and means for imparting reciprocating motion to the cylinder. A piston having a log striking end is slidably mounted in the cylinder. The piston is resiliently biased so that the log striking end thereof normally extends beyond the open end of the cylinder. The log striking apparatus and backstop are positioned relative to the conveying means such that, on the forward stroke of the cylinder, the log striking end of the piston strikes a log, the log being pushed across the conveying means against the backstop.- Unduly long logs cause the piston to travel backwards in the cylinder so as to prevent the apparatus from jamming.

Referring to the drawing for a more detailed description of my invention, I have shown a log aligning apparatus which comprises a reciprocating cylinder 6 mounted in a pair of bearings 7 and slidable therein. Reciprocating cylinder 6 has an open end on the righthand side thereof. A yoke 17 having pins 16 extending therefrom is secured to reciprocating cylinder 6 at the left-hand end thereof. The two arms of a Y-sha'ped connecting rod 2 have bushings 18 therein into which fit pins 16. Connecting rod 2 thus is pivotally connected to reciprocating cylinder 6. The other end of connecting rod 2 is provided with a bushing 19 into which fits a pin 20 eccentrically located on a flywheel 1. Thus connecting rod 2 is pivotally and eccentrically connected to flywheel 1. Flywheel 1 is keyed to a rotating shaft 21 which may be connected to an electric motor (not shown), preferably of the variable speed type, by means of a V belt drive or through suitable reduction gearing.

Slidably mounted in reciprocating cylinder 6 is a piston 9 which is permitted free reciprocating travel within limits which can be preset and varied if desired, as will become apparent hereinafter.

A source of compressed air (not shown), preferably a source which will provide compressed air of variable pressure, is connected to a chamber 10 within reciprocating cylinder 6 by means of an inlet 11. Suitable seals are provided at both ends of reciprocating cylinder 6 in order to prevent the escape of compressed air therefrom.

A compression spring 12 is positioned between one end of reciprocating cylinder 6 and a collar on the rod portion a of piston 9.

A moving conveyor belt 13 is provided, and a plurality of logs 14 is positioned side by side on conveyor belt 13. The conveyor may be driven by an electric motor, and the belt thereof passes over rollers 15.

In the operation of the embodiment of my invention shown in the figure, logs 14 are discharged from a barking drum onto conveyor belt 13 in such a manner that they he regularly across the conveyor belt. The electric motor connected to flywheel 1 imparts a forward and backward motion to reciprocating cylinder 6 through connecting rod 2. The speed of the variable speed electric motor driving flywheel 1 is adjusted so that the log striking end of piston 9 can strike each log 14 in turn if the conveyor belt is full, i.e., if there is a continuous supply of logs laid side by side and touching each other on conveyor belt 13.

It will be apparent from a consideration of the drawing that as reciprocating cylinder 6 advances towards log 14, piston 9 will strike the log and will push it to the other side of the conveyor. At the other side of the conveyor a backstop 30 is provided against which log 14 abuts when pushed from one side of the conveyor to the other by piston 9. Piston 9 is shown in its normal position in the figure, i.e., its fully extended position for the particular air pressure employed.

However, it will be seen that some means is necessary in order to compensate for logs of varying lengths, because the stroke of reciprocating cylinder 6 is constant and is determined by the eccentricity of crosshead pin 20 on flywheel 1. The means for providing this compensation is piston 9. The compressed air in chamber 10 acts as a cushion behind piston 9 and resiliently biases the piston while log 14 is being pushed across conveyor 13 to abut against the backsto and the compressed air cushion offers sufiicient resistance to enable log 14 to be pushed across the conveyor. However, if log 14 is of such a length that it abuts against the backstop before reciprocating cylinder 6 and piston 9 have completed their full forward stroke to the right, piston 9 will be forced to the left into reciprocating cylinder 6 against the compressed air cushion in chamber 10. In this manner logs of varying lengths may be abutted against the backstop without causing the mechanism to jam. Thus it will be apparent that the compressed air in chamber 10 resiliently biases piston 9 to a position such that normally the log striking end of piston 9 extends beyond the open end of cylinder 6. The extent to which piston 9 extends out of cylinder 6 is determined by the pressure of the compressed air in chamber 10 and the force exerted by compression spring 12. The position of the log striking end of piston 6 may be varied by altering the air pressure in chamber 10.

The primary function of spring 12 is to act as a cushion to prevent the collar on the rod portion of piston 9 from striking reciprocating cylinder 6. During periods when there are no logs 14 on conveyor belt 13, or there are gaps between the logs, but the log aligning device is still executing reciprocating motion, the collar on the lefthand end of the rod portion of piston 9 would slap against the end of reciprocating cylinder 6 if spring 12 were not provided. Continued slapping might cause either reciprocating cylinder 6 or the collar to fail. Spring 12 acts as a cushion and prevents such damage. The spring also contributes to reducing the amount of noise during the operation of the log aligning device.

The main reason that chamber is connected to a source of compressed air of variable pressure is to permit the operators to have more control over the log aligning evice to suit varying wood sizes. For example, there may be periods during the operation of the device when logs 14 on conveyor belt 13 are of large diameter or of small diameter. Since it requires more eflort to push larger logs across conveyor belt 13, the air pressure in chamber It) may be increased in order to provide the necessary resistance behind piston 9. Where logs of smaller diameter are being processed, the air pressure in chamber 10 can be reduced. Where logs of both large and small diameter are positioned side-by-side on conveyor belt 13, a suitable air pressure may be selected by the operator relying on his previous experience.

On the backstroke of reciprocating cylinder 6 piston 9 takes up its extended position shown in the figure because of the pressure of the compressed air within chamber 10, and piston 9 is then ready to operate on the next log on the forward stroke of the reciprocating cylinder 6.

While in the preferred embodiment of my invention I have used compressed air as the means for resiliently biasing piston 9, it will be apparent to those skilled in the art that any hydraulic fluid may be employed with similar results. Of course, it will be appreciated that if an incompressible hydraulic liquid is employed, it cannot be sealed in chamber 10 or piston 9 would not be resiliently biased. A suitable escape valve must be used in such a case, and such a valve could be associated with the source of hydraulic liquid connected to inlet 11. It will also be apparent that a compression spring could be employed with equal effectiveness. If a compression spring is employed, it will be understood that in order to alter the force exerted against piston 9 from within cylinder 6, a spring having a different spring constant would have to be substituted for the original spring. Obviously, since this would require dismantling of the unit, it is less convenient than employing a source of variable air pressure.

From a consideration of the foregoing disclosure, it will be seen that I have provided a log aligning device which automatically operates so as to align endwise a plurality of logs on a moving conveyor in such a manner that one end of each of the logs is aligned with one another, so that an operator (or a mechanical sorter) standing further down the conveyor line can readily pick out logs of required lengths and separate and classify the same for use in future operations.

While I have disclosed certain preferred embodiments of my invention, it will be apparent that various modifications and changes may be made therein without departing from the spirit and scope of my invention as defined in the appended claims.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A log aligning device for aligning logs endwise comprising means for conveying a plurality of logs lying one beside another in substantially parallel relationship, a backstop positioned on one side of said conveying means and a log aligning apparatus positioned on the other side of said conveying means opposite said backstop, said log aligning apparatus comprising a cylinder having an open end, means for imparting reciprocating motion to said cylinder, a piston slidably mounted in said cylinder and having a log striking end, and means resiliently biasing said piston to a normal position, said log striking end of said piston in said normal position being substantially beyond said open end of said cylinder, said log striking apparatus being positioned relative to said logs to push a log across said conveying means against said backstop on the forward stroke of said cylinder, said log striking end of said piston contacting one end of said log during said forward stroke, the other end of said log being abutted against said backstop during said forward stroke.

2. A log aligning device according to claim 1 wherein said means for imparting reciprocating motion to said cylinder comprise a rotatable flywheel and a connecting rod pivotally connected to said cylinder and eccentrically pivotally connected to said flywheel.

3. A log aligning device according to claim 1 wherein said means resiliently biasing said piston is compressed air.

4. A log aligning device according to claim 1 wherein said means resiliently biasing said piston is a hydraulic fluid.

5. A log aligning device according to claim 1 wherein said means resiliently biasing said piston is a spring positioned within said cylinder and behind said piston.

6. A log aligning device for aligning logs endwise comprising means for conveying a plurality of logs lying one beside another in substantially parallel relationship, a backstop positioned on one side of said conveying means and a log aligning apparatus positioned on the other side of said conveying means, said log aligning apparatus comprising a cylinder having an open end, means for imparting reciprocating motion to said cylinder, a piston slidably mounted in said cylinder and having a log striking end, a chamber within said cylinder behind said piston, means for introducing a hydraulic fluid into said chamber to resiliently bias said piston to a normal position, said log striking end of said piston in said normal position being substantially beyond said open end of said cylinder, and means to restrict movement of said piston in said cylinder within predetermined limits, said log striking apparatus being positioned relative to said logs to push a log across said conveying means against said backstop on the forward stroke of said cylinder, said log striking end of said piston contacting one end of said log during said forward stroke, the other end of said log being abutted against said backstop during said forward stroke.

7. A log aligning device according to claim 6 wherein said hydraulic fluid is compressed air.

8. A log aligning device according to claim 7 wherein said means for introducing compressed air into said chamber includes a source of compressed air of variable pressure.

9. A log aligning device according to claim 7 wherein said means for imparting reciprocating motion to said cylinder comprises a rotatable flywheel and a connecting rod pivotally connected to said cylinder and eccentrically pivotally connected to said flywheel.

References Cited in the file of this patent UNITED STATES PATENTS 2,816,645 Norin Dec. 17, 1957 

